digital HPT HCg Levels?

Brittany • Mom to 3 boys and a baby girl 💙💙💙💖
So I've been freaked out Bc after a trip to the ER last I found that at 3 weeks 5 days my HCg Levels are/were 17. I'm thinking that's low and being I've had a miscarriage before this I started assuming the worst. BUT today I took a digital test and regular test. The regular one WAS darker than yesterday's by some degree and the digital said pregnant. Do u guys think I'm safe to say maybe the levels went up? Or are digitals able to read + with HCg Levels of 17? Also since the other test got darker can I assume at least my levels have not decreased due to failing pregnancy or would they not decrease in a days time? Sorry so many questions, just worried. Thanks for any help. I'm constantly praying that this pregnancy makes it.